#include <iostream>
#include <vector>
#include <stack>
#include <string>
#include <cassert>

struct pavouk {
    char jmeno;
    int levy = -1, pravy = -1; // indexy v poli pavouci
};

std::vector<pavouk> pavouci;
std::string radka;
std::string::iterator it;

bool je_jmeno_pavouka(char znak) {
    return znak >= 'a' && znak <= 'z';
};

// vytvori noveho pavouka a vrati jeho index
int novy_pavouk() {
    int p = pavouci.size();
    pavouci.push_back(pavouk());
    return p;
}

const int NENI_POTOMEK = -1;
const int CHYBA_CTENI = -2;

void precti_vstup() {
    std::getline(std::cin, radka);
    it = radka.begin();
}

char nacti_jmeno() {
    char jm = *it;
    if(je_jmeno_pavouka(jm)) {
        it++;
        return jm;
    } else {
        return CHYBA_CTENI;
    }
}

int nacti_pavouka() {
    if(je_jmeno_pavouka(*it)) { // pavouk bez potomku
        int p = novy_pavouk();
        pavouci[p].jmeno = *it;
        it++;
        return p;
    } else if(*it == '_') {
        it++;
        return NENI_POTOMEK;  
    } else if(*it == '(') { // pavouk s potomky
        int p = novy_pavouk();
        it++;
        int levy = nacti_pavouka();
        char jmeno = nacti_jmeno();
        int pravy = nacti_pavouka();
        if(levy != CHYBA_CTENI && jmeno != CHYBA_CTENI && pravy != CHYBA_CTENI && *it == ')') {
            pavouci[p].levy = levy;
            pavouci[p].jmeno = jmeno;
            pavouci[p].pravy = pravy;
            it++;
            return p;
        } else {
            return CHYBA_CTENI;
        }
    } else {
        return CHYBA_CTENI;
    }
}

bool konec_radky() {
    return it == radka.end();
}

void vypis(int p, std::string& buffer) {
    buffer.resize(buffer.size() + 1, pavouci[p].jmeno);
    if(pavouci[p].levy == NENI_POTOMEK && pavouci[p].pravy == NENI_POTOMEK) {
        std::cout<<buffer<<std::endl;
    } else {
        if(pavouci[p].levy != -1)
            vypis(pavouci[p].levy, buffer);
        if(pavouci[p].pravy != -1)
            vypis(pavouci[p].pravy, buffer);
    }
    buffer.resize(buffer.size() - 1);
}

int main() {
    precti_vstup();
    int p = nacti_pavouka();

    if(p == CHYBA_CTENI || !konec_radky()) {
        std::cout<<"chyba"<<std::endl;
    } else if(p >= 0) {
        std::string buffer = "";
        vypis(p, buffer);
    } else if(p == NENI_POTOMEK) {
        std::cout<<"nikdo"<<std::endl;
    } else {
        assert(false);
    }
    return 0;
}